In recent years, a headlight control system for assisting a driver of a vehicle to recognize an object such as a pedestrian or the like without alerting the pedestrian has been proposed (refer to Japanese Patent Document JP-A-2000-203335). In the disclosure of this Japanese Patent Document, the headlight control system includes a first headlight for projecting a visible light toward a front space of the vehicle and a second headlight for projecting an ultraviolet light toward a front space of the vehicle. The ultraviolet light projected from the second headlight shines on clothes worn by the pedestrian, and reflects back toward the driver of the vehicle. That is, the pedestrian is lit up by the ultraviolet light. Therefore, the driver of the vehicle can visually recognize the pedestrian ahead of the vehicle, and the pedestrian is not alerted by the ultraviolet light even when he/she sees the ultraviolet light from the second headlight.
However, reflection intensity of the ultraviolet light used in the conventional headlight control system is affected by the color and material of the clothes of the pedestrian. That is, the intensity of the reflection of the ultraviolet light varies largely depending on the color of the clothes or the like. In addition, the driver can hardly recognize a small animal such as a dog, a cat or the like that may be lit up by the ultraviolet light because their coats are not very reflective.